With the discovery of the Higgs boson at the LHC in 2012, coupled with the absence of other phenomena, the particle physics panorama has become, surprisingly perhaps, very open. While the Standard Model could appear as a complete theory, several undeniable observations tell us that there is more to the story. The nature of dark matter, the origin of the baryon asymmetry in the universe, the mysteries lying behind the very small neutrino masses are telling us to keep looking for answers. Are the required new phenomena to be found at higher energies, or have they escaped detection because of very small couplings? The FCCs will address these fundamental open issues of particle physics.

The FCC-ee, formerly known as TLEP, is a high-luminosity, high-precision e+e- storage ring collider. In the context of the FCC, the design study of Future Circular Colliders at CERN, FCC-ee would be the first step towards the long-term goal of a 100 TeV proton-proton collider. The basic design with a top-up booster and separate e+ and e- channels, inspired from B factories, allows very large luminosities to be contemplated in up to four interaction points. In a 80-100 km tunnel, the accessible centre-of-mass energy range spans the range from the Z pole (90 GeV) to above the top pair threshold (~400 GeV). This collider offers unique sensitivity to new physics, not only at very high mass, but also if very weakly coupled to standard particles.

The expected luminosity performance of FCC-ee/TLEP lead to the production of a Tera Z, several Oku W, several Mega Higgs and a Mega top, i.e., orders of magnitude above other projects on the market. Such large statistics samples allow the measurement of the properties of these particles with unprecedented accuracy, and are the tool of choice to discover and study rare Z, W, Higgs boson and top decays. Besides offering the ultimate investigations of electroweak symmetry breaking, these precision measurements would be highly sensitive to the possible existence of yet unknown particles, with masses up to 100 TeV. Sensitive searches for particles with couplings much smaller than weak, such as ‘sterile neutrinos', can be envisioned. Click on the figure to access to the original article 'A first look at the physics case of TLEP'.

FCC-ee

The FCC-ee in a few words

The FCC-ee, formerly known as TLEP, is a high-luminosity, high-precision e+e- circular collider envisioned in a new 80-100 km tunnel in the Geneva area. With a centre-of-mass energy from 90 to 400 GeV, the physics program could pave the way towards the discovery of physics beyond the Standard Model, casting light on unanswered questions, such as dark matter, the baryon asymmetry of the Universe, the hierarchy problem, the stability of the Universe or the nonzero neutrino masses.

The FCC-ee project is part and parcel of the Future Circular Collider design study (FCC) at CERN, and would be the first step towards the long-term goal of a 100 TeV proton-proton collider. It is expected to deliver its conclusion in 2018, just prior the next update of the European Strategy. There are many challenges facing the study, starting with a realistic design that allows these promises to be fulfilled, so feel free to join the design study group if you wish to collaborate with us!

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A prototype for the final focussing quadrupole of the FCC-ee was 3D-printed over Xmas, for tests and measurements. Congratulations to Mike Koratzinos and magnet group for this achievement.

5 Mar 2015 :
Machine's potential once again enhanced

FCC-ee could measure the top quark electroweak couplings with unprecedented precision through the top pair production in semileptonic decays. Check the paper here.

27 Jan 2015 :
Societé Française de Physique supports FCCs

The Fields and Particles division of the "Societé Française de Physique" encourages the study of an e+e- collider to measure the Higgs, top, Z and W properties. Check the conclusions delivered after the "Journée: Futur de la Physique des particules", at LPNHE, Paris, and Patrick Janot's FCC talk in this context.

Highlights

20 Nov 2015 :
Article in the CERN Courrier

The FCC-ee mini-workshop on the strong coupling constant (alpha_s) is featured in the CERN Courrier and in the CERN/PH news this month ! You can browse the very interesting presentations in the corresponding indico agenda.

30 Mar 2015 :
FCC Week 2015 is over

The first annual meeting of this visionary study marked a milestone of the first exploratory study phase. 340 participants and 290 contributions from all domains of the study gave impressive evidence of the progress achieved and the challenges ahead.

20 Jan 2015 :
FCC Weeek 2015

One year after the FCC kick-off meeting, the first annual meeting of the Future Circular Collider study is taking place in Washington on the 23rd-27th March. The purpose is to conclude the first exploratory phase and identify the baseline for the further study. Don't miss this very important milestone!

Frederick Bordry will introduce the general public to the feasibility of designing, building and operating the FCC, as well as the different machine options (hh,ee,he), at the CERN Globe on the 11th March. Registration is mandatory here.